Mixer for lightweight concrete



M. JANHUNEN MIXER FOR LIGHT Oct. 23, 1951 WEIGHT CONCRETE 2 SHEETS-SHEET 1 Filed Feb. 25, 1948 INVENT OR /0 N Ja m a M ATTORNEYS Oct; 23, 1951 M. JANHUNEN 2,572,345

MIXER FOR LIGHT-WEIGHT CONCRETE Filed Feb. 25, 1948 2 SHEETS-SHEET 2 ATTORNEYS Patented Oct. 23, 1951 UNITED STAT ES PATENT OFFICE IVHXER FOB CONCRETE Matti J anhunen, Helsinki, Finland Application .February25, 1948, Serial No. 10,842 In Sweden April 21, 1947 '6 Claims. (Cl. 259-178) FFQI building purposes there is being produced porous building stones of various materials, which is binding and hardening in connection -with water, in which foam building materials are added. It is advantageous to use a mixture of cement, sand and water, to which ,is added foaming substances either in their original form, or in the foam produced separately and added to the mixture afterwards. The mixture is to be carefully stirred, so that the foam bubbles are evenly divided over the whole bulk of mixture.

This invention relates to a method for producing of such light-weight concrete by means of a mixer, which has `on its rotating axle secured for instance by means of arms or the like constructed Wings `of wire-netting or perforated material, made to rotate in a drum with filling and discharging openings. In so far known mixers of this type the wings have generally been constructed in a mainly radial direction. The Working capacity has in these mixers not been wholly satisfactory, which should depend upon that the effect of the portion of the wings, which is near the axle, is smaller and, on account of that this mixing mainly is taking place away further off from the portion of the wing which is closer to the axle. There is also a mixer known, which has arched or cylindrical mixing organs of perforated material arranged to form a spiral. The space between these organs is, however, very small and they lare difficult to keep clean, which is quite necessary when there is a question of handling such hardening material, which, even if it remains on the surface of the mixing organs in thin layers, very soon closes the perforation. Also .the working capacity of these mixers is unsatisfactory, on account of which they have not been adopted for use in practical service.

Above invention has for its purpose to eliminate these disadvantages and is referring to a mixer, which to its general form is characterized by that each wing is having a sloping position thus, that the mainly axially running outer edge of the portion of the wing near the mantle of the drum is moving before or after, depending on direction of rotation, and the base edge of the wing, likewise having an axial direction, is moving correspondingly after or before as well as closer to the axle than the outer edge.

According to a suitable way of construction each one of the wings extends from axial bars, carried by arms secured to the axle, right to the base which is mounted-depending on direction of rotation-to arms behind, between the axle and the ends. The base can conveniently be secured to the arms behind about in the midway or somewhat towards the axle from the middle.

The invention is illustrated by the accompanying drawings, which schematically and in a reduced scale are showing a form of construction in this invention. Figure 1 shows a section through the wing system vertically towards the axle and Fig. 2 is a section of the axle through the mixer. Figure 3 is showing a detail.

I illustrates the axle of the mixer and 2 the wings made of wire-netting. The wings are rotating in the drum 3. Secured to axle I are arms 4, supporting bars 5. The edges of the wings are fastened to these bars conveniently in a way shown in Fig. 3 in an enlarged scale. Each one of the wings 2 is stretched between bar 5 and its base` 6. The bases of the wings are in the illustratedxconstruction fastenedafter taking into consideration the direction of rotationto the arm at the back by means of connecting members l, in a way shown in Fig. 1.

According to the invention there is further to be observed, that the slope in the Wings is adjustable after the Working effect of the mixer and the density of the mass that comes into question. For this purpose the connecting members 1 on the wing bases can in some known way be made to slide along the arm 4, thus making it possible in each special case to attain a best possible working effect.

By a special way of construction the wings can by means of thumb screws, wingnuts or similar fastening organs be mounted in an easily removable way. In such case the wings can in a convenient way be detached for cleaning, repair or exchange.

Experiments have proved, that the above described mixer has a far greater effect resp. working capacity than the earlier known ones, and at the same time the quality of the mass mixed has proved to be better. This should be depending on that the mass near the axle is weltered over the sides of the wings, being thus continually placed before the next wing in order to be treated by this.

The invention has here above been explained in connection with production of a porous mass by the use of cement. But the invention is, of course, also applicable when other hardening materials, such as plaster of Paris, are used for producing of porous masses.

As a filling material there can be used besides sand also other matters such as kieselguhr,

asbestos bres, sawdust or the like, or a mixture of different materials. The invention has furthermore been described only as an example of construction, in regard to which many alterations can be made without departing from the idea. of the invention. Thus can, for instance, the wirenetting on the wings be in several layers, so that there is left a space between each of the netting layers. Experiments executed have proved, that specially good results have been obtained by using wings with double wire-netting layers. The number of wings can also be other than 4, viz., for inst., 3 or 6.

. Having thus described my invention, what I claim and desire to secure by Letters Patent, is:

1. A concrete mixer comprising a drum, a shaft rotatably mounted insaid drum, arms xed to said shaft and extending radially therefrom and perforated wings mounted on said arms, one side edge of each wing being fixed to the free end of one of said arms and theopposite side edge being xed to an intermediate point of the following arm so that each wing extends parallel to said shaft and inclined to a radius of said shaft.

2, A concrete mixer comprising a drum having inlet and outlet openings, a horizontally extending shaft rotatably mounted in Said drum, arms xed to said shaft and extending radially therefrom and perforated wings mounted on said arms, one side ed-ge of each wing vbeing fixed to the free end of one of saidarms and the opposite side edge being xed to an intermediate point of the following arm so that each wing extends parallel to said shaft and inclined to a radius of said shaft.

3. A concrete mixer comprising a drum, a shaft rotatably mounted in said drum, arms fixed to said shaft and extending radially therefrom, bars fixed to the free ends of said arms and extending parallel to said shaft and wings of perforated material having one side edge fixed to said bars and the opposite side edge to an intermediate point on said arms.

4. A concrete mixer comprising a drum, a shaft rotatably mounted in said drum, arms xed to said shaft and extending radially therefrom, bars xed to the free ends of said arms and extending parallel to said shaft and wings of perforated material having one side edge detaohably fixed to said bars and the opposite side edge detachably xed to an intermediate point on said arms.

5. A concrete mixer comprising a drum, a shaft rotatably mounted in said drum, arms xed to said shaft and extending radially therefrom, bars fixed to the free ends of said arms and extending parallel to said shaft and Wings of perforated Inaterial having one side edge detachably fixed to said bars and the opposite side edge detachably fixed to approximately the central point of said 6. A concrete mixer comprising a drum, a shaft rotatably mounted in said drum, arms fixed to said shaft and extending radially therefrom, bars xed to the free ends of said arms and extending parallel to said shaft and wings of perforated material having one side edge detachably xed to said bars and the oppositeside edge is adjustably` fixed to an intermediate point on said arms so that the inclination of said wings with relation to a radius of said shaft may be Varied.

MATTI JANHUNEN.

REFERENCES CITED The following references are of record in th file of this patent:

UNITED STATES PATENTS Number Name Date 65,014 Sanborn May 21, 1867 171,331 Watson Dec. 21, 1875 299,685 Schwarzchild June 3, 1884 592,708 Howe Oct. 26, 1897 1,158,188 Doyle Oct. 26, 1915 ,v 1,525,394 Jolicoeur Feb. 3, 1925 

